The present invention relates to product bags and, more particularly, to product bags supportable on support wickets.
Bags supported and dispensed by wickets are in common use for packaging operations which require a large number of bags for packaging products such as food products, manufactured articles, and apparel. Normally, a group or stack of bags are supported on a structure by the prongs of the wickets inserted in wicket holes in the bags. The bags are removed from the wicket by pulling or otherwise providing a removal force which tears or extends the wicket hole to the top edge of the bag, releasing the bag. This support means allows quick and easy removal of the bags before or after product filling.
Wicket bags normally comprise a lip or raised back panel. These bags, often called "side sealed" bags are made by folding a film web, forming the bottom of the bag and leaving an overlapping lip on the back panel. The bag is completed by side welding or sealing the bag, and cutting lengthwise. The wicket holes in a lip type bag extend through the back panel, but not normally through the front panel. In this manner, the front panel is easily opened since it is not restrained by the wicket prongs. The bag is easily filled with product, and is easily removed since the front of the bag may be gripped by the hand or automated equipment.
Lipless bags, also called "bottom seal" bags, are popular in the packaging industry due to their simplicity and ability to be made quickly and economically. For example, lipless bags are made from seamed or seamless film tubes by seal welding the bottom and then slitting transversely during or after the weld. The weld provides the bottom of the first bag and the slit forms the top of the next sequential bag. Gussets may be formed in the sides of the bag during manufacture and provide better product fit and additional bag capacity.
A problem arises when supporting lipless bags on wickets since wicket holes extend through the front of the bag as well as the back of the bag. The front of the bag is difficult to open and grip for filling and bag removal since the wicket prongs retain the front of the bag on the support. This is especially a problem for highly repetitive operations, since extra separation force is required to separate the front of the bag from the wicket. Such a method increases the possibility of operator fatigue, and missed bagging operations, whether done manually or by automated equipment. Converting a lipless bag into a lip type bag requires additional manufacturing steps which add cost and slow the bag-making process.